It would be great to use Nicepage to create blog posts and customize Woocommerce just the way we create pages (the way Themler used to work). But besides the question. I have a workaround to create stunning blog posts with Nicepage.
First, you have to install the Post Type Switcher and activate it.
Then create a page with Nicepage.
Then go to all pages and find your newly created page.
Click on "Quick Edit"
Find the "Post Type" drop-down.
Change it from "Page" to "Post" then Update
Go to Posts
Locate your post and click on "Quick Edit"
Select it into the correct blog category and make other changes if required.
Update
Maybe there are other ways to do this, but this is the route that I took.